One of the most successful and highly regarded coaches in college football history, Osborne, 75, also served a stint in Congress. He returned to Lincoln five years ago to become the NU Athletic Director after the prestigious Husker football program faltered.

Osborne said he is in good health, but has reached a point when he wants to step aside. He will stay around for six months or so after a new Athletic Director is selected in order to help with a smooth transition.

Osborne was the head coach of the Huskers team for 25 years, from 1973-97, succeeding the legendary Bob Devaney. After coaching, Osborne was elected to Congress in 2000. He served six years in the U.S. House of Representatives as a Republican from Nebraska's third district.

He returned to the Huskers in 2007.

News of his retirement prompted tributes from Nebraska’s top office holders.

Sen. Ben Nelson said he and Osborne have been friends since they were students at the University of Nebraska and lived in the same duplex in Lincoln.

“In all those years and in every endeavor he has always conducted himself with honor, integrity, passion and compassion,” Nelson said.

“Nebraska is a far better place because of the good work done by this living legend,” Nelson said.

Sen. Mike Johanns said “Tom is a good friend and a life-long public servant. From Husker arenas to the halls of Congress, he has made a profound and positive impact on countless student-athletes and all Nebraskans.”

“I want to thank Tom for his service to our state and special focus on young people both on the field and through the Teammates program,” Johanns said.

“He is the greatest collegiate football coach of all time,” Gov. Dave Heineman said. “When he became the athletic director five years ago, Tom immediately restored trust, confidence and stability in University of Nebraska athletic programs.”

"Coach Osborne is a legend not only because of his success as a football player and coach, but also because of his life-long dedication to our state and service to others," Rep. Adrian Smith said.